The current oil extraction system worldwide consists of a nodding donkey, sucker and polish rods and a pump. The nodding donkey is the overground drive for the submersible pump in a borehole. The rods connect the head to the pump located thousands of meters underground. The reciprocating pump plunger lifts oil to the earth's surface. The current pump system has a series of disadvantages: 1) Large size and high cost. 2) Inefficiency. Most of the power is consumed by the thousand-meter-long rods' reciprocation. Only a small portion of the power is used for lifting petroleum-water mixture. 3) It is very hard for the reciprocating rods to always keep parallel to the oil tube center line, often resulting in rod breakage due to friction. A hole in the pump cylinder may even be worn by friction. 4) The only way to increase strength of the superlong rod is to increase rod section, resulting in heavier rod deadweight further. So current well depth is limited to 2400 meters. 5) The current oil extraction system, especially the superlong rods, not only needs larger investment, but also needs more operating time and cost. Further more, rod extension of 0.6 meter in one thousand meters decreases stroke and affects pump efficiency. 6) Residue in the petroleum-water mixture can only deposit on the plunger top. This may stop the pump during plunger's up stroke. 7) In poor oil wells, pump plunger's no-load operation leads to dry friction between the plunger and the pump cylinder, wasting energy and annealing the plunger and the pump cylinder. 8) Usually, natural gas is present in oil wells. The plunger's down stroke is made by gravity. Compressed natural gas prevents the plunger from reaching its dead end. Resultant “gas lock” affects normal oil extraction operation. Gas discharge has to be made if serious. 9) Sometimes, especially in old, low-production wells without enough liquid, current oil extraction system can only work intermittently (extraction parameters can be adjusted in limited extent). If the pump stops, restarting is very difficult or in some cases even impossible. So all rods and pump have to be drawn to the ground and then put them down again in the oil well.